﻿class Solution {
public:
    int lengthOfLIS(vector<int>& nums) {
        int n = nums.size();
        vector<int> ret;
        ret.push_back(nums[0]);
        for (int i = 1; i < n; i++) {
            if (nums[i] > ret.back()) // 如果能接在最后⼀个元素后⾯，直接放
            {
                ret.push_back(nums[i]);
            }
            else {
                // ⼆分插⼊位置
                int left = 0, right = ret.size() - 1;
                while (left < right)
                {
                    int mid = (left + right) >> 1;
                    if (ret[mid] < nums[i])
                        left = mid + 1;
                    else
                        right = mid;
                }
                ret[left] = nums[i]; // 放在 left 位置上
            }
        }
        return ret.size();
    }
};
